Universal Serial BUS (USB) is an industry protocol designed to standardize the interfaces between computer devices for communication and supplying electrical power. The USB protocol has enjoyed widespread adoption in nearly every computing device, and has received tremendous support in terms of technology development with well-established intellectual property (IP) portfolios and standardized software infrastructure. USB interconnects are used in inter-chip communications and to connect devices through cables.
Transmission of electrical signals in a circuit board can result in signal loss. The signal loss is usually dependent on the frequency of the transmission. For example, signal loss will generally be higher at higher frequencies. The signal loss variation across the frequency range of a signal can make it more difficult for signal receivers to recover the transmitted data. Accordingly, signal equalization techniques are used to equalize the frequency dependent loss.